The purpose of this invention is to greatly extend the memory capacity and useful lifetime of existing computers by providing a means of accessing a large external memory bank without requiring changes to existing operational program modules.
The Navy has grossly outgrown the memory capacity of its shipboard computers, which were designed to have a maximum memory size of 32,768 words. The prior art solution was to add more computers, and some ships now have as many as four computers, each having access only to its own internal memory. This procedure is an unsatisfactory way of adding memory to the system, since a very large volume of inter-computer communication must occur just to keep each machine's data base updated. This is a slow process since it must take place under program control (which robs time from worker programs) and at input/output speeds which are very much slower than memory speeds.